1. Field of the Invention
This invention relates to a non-toxic method of exterminating undesirable organisms. More specifically, this invention teaches a method and apparatus utilizing a vortex tube which also has been known as Ranque-Hilsch tube to provide lethal temperatures to destroy undesirable organisms such as insects, termites, mildews or tumors in human body.
2. Description of the Prior Art
Most lenders require that homes be certified termite-free when sold. In the art as practiced today there are many well known techniques for inspecting a dwelling to discover and locate termites. These include visual inspection, acoustic techniques and fiber optics which are successful in determining the location of colonies of termites that should be removed and exterminated.
Undesirable organisms such as termites, insects, mildews and rodents are conventionally destroyed by chemical means. For example, termites are commonly treated by tenting the complete structure and utilizing fumigants such as methyl bromide. Tenting a structure is both time-consuming and disruptive to residents. A minimum of two or three days is necessary to allow the poisons to thoroughly permeate the entire structure. Accidental deaths caused to exterminators and others who inadvertently are overcome and killed by the handling or mishandling poisonous fumigants are occasionally reported in the news. In addition, some of the most widely used chemicals have been linked to birth defects and cancer. Consequently, chlordane is banned for use against termites, methyl bromide and sulfuryl fluoride (Vikane) are more tightly regulated. Based on recent studies that show methyl bromide to be more destructive to the Earth's ozone layer than chlorofluorocarbons (CFC), some environmental groups are calling for a ban on chemicals and searching for alternative environmental-safe methods.
Any of the organisms including insects, termites, mildews and rodents, has a normal temperature range within which it can survive and thrive. This normal range may vary from species to species. Temperature appreciably outside of the normal range is lethal especially if it is maintained for a long period of time. Very high temperatures will melt or crack the wax layer carried by many insects, and will cause them to dehydrate and die. Very low temperatures will freeze the bodily fluids of many insects and animals, and kill them. The precise mechanism by which organisms perish is of no concern here. Only the fact that organisms perish at either elevated or sub-freezing abnormal temperatures is the point of interest.
Exterminating insects by freezing liquid or by heat has been proposed separately in earlier inventions. In U.S. Pat. No. 5,027,546, Tallon discloses the use of freezing liquid to exterminate insects in structure. A temperature of 0.degree. F. for 5 minutes will kill termites and fire ants. To ensure that all infestation have been destroyed, a temperature of -20.degree. F. is needed. Tank of liquid nitrogen needs to be hauled to work area and gravity is utilized to control the flow into right enclosed place. The feeding port of liquid gas has to be put higher than the infestation area. Since liquid nitrogen can be as cold as -320.degree. F., severe caution is needed in handling it to prevent cold burn. In U.S. Pat. Nos. 4,817,329 and 4,961,283, Forbes discloses extermination of insects by heat. In U.S. Pat. No. 5,058,313, Tallon utilizes heat in exterminating structure infestations. Typically a temperature of 155.degree. F. is used to kill insects. Heat is usually generated by burning flammable fuel such as propane. Extreme caution is required in handling such flammable materials to prevent fire hazard.
Radiation and surgery are the common methods to treat early stage, localized tumors in human body. Abnormally low and high temperatures are also known to be detrimental to tumors. Recently, liquid nitrogen has been used experimentally in some hospitals to treat localized tumors by cooling it down to sub-freezing temperatures.
The application of freezing cold or heat to eliminate mildews is nowhere shown or suggested in any of the prior references or records available to the inventor. In addition, to the best knowledge of the inventor, there has never been an invention that has the ability to offer both freezing and heat treatments in a single unit for exterminating organisms.